Field of Invention
The invention relates generally to instruments for examining and treating the eye, and specifically to a version of the electronic ophthalmoscope combining SLO (scanning laser ophthalmoscopy) and OCT (optical coherence tomography) designs, and further equipped with an ultra fast pulsed laser source for administering selective retinal photodisruption laser therapy to the photoreceptor mosaic layer of the retina.
Description of Prior Art
The ophthalmoscope is well known as an important device for examining the eye, and in particular the retina. As a result of great interest in preserving eyesight, ophthalmoscopes of various constructions have been built. An electronic version of the ophthalmoscope, as described in U.S. Pat. Nos. 7,374,287 and 7,703,922, combining optimally scanning laser and optical coherence technologies, is particularly appealing because of its unique capability of combining a high resolution and high contrast 3-D infra-red or angiographic “real-time” video imaging of the retina with psychophysical procedures such as microperimetry (MP). A precise correlation between retinal anatomy and retinal functioning can be established with the scanning laser ophthalmoscope. This retinal function mapping reveals information about fixation behavior, visual acuity and retinal sensitivity, and is now known to be very helpful to the surgeon when applying various forms of therapeutic laser and for the purpose of low vision rehabilitation.
Van de Velde has disclosed before in U.S. Pat. Nos. 5,892,569, 5,923,399, 5,943,117, 6,186,628 and 6,789,900, which are all herein incorporated by reference, different embodiments of the relaxed confocal scanning laser ophthalmoscope that use various external light sources for therapeutic and diagnostic applications. Such functional extensions rely to a great extent on a relaxed confocal optical design of the SLO, incorporating one or two synchronized avalanche photodetector pathways that feed their signal into a versatile overlay frame grabber imaging board. U.S. Pat. No. 6,789,000 describes methods to selectively deliver therapeutic laser energy to the retinal pigment epithelium (RPE). They employ for example acousto-optic technology to create an appropriate duty-cycle for the laser applications. The short duration thermal applications are intended to limit the destructive laser tissue impact to the RPE layer. The delivery of sufficient energy to the photoreceptor layer (PR) in a confined manner and sparing as much as possible the choriocapillary layer (CC) and inner retinal layers, remains challenging. The aforementioned electronic ophthalmoscope can be equipped with newer short pulse femtosecond laser sources to achieve this goal.
Additional technical information regarding the electronic ophthalmoscope and its possibilities, especially with regard to the treatment of various forms of age-related maculopathy (ARM), can be found in the following texts, all included by reference:                1. Frans J. Van de Velde. Quantitative SLO microperimetry for clinical research in age related maculopathy. In: Noninvasive assessment of the visual system: from the Topical Meeting Vision Science and its Applications, Jan. 31-Feb. 3, 1997, Santa Fe, N. Mex./edited by Dean Yager; sponsored by Optical Society of America; in cooperation with the American Academy of Optometry. Published/Created: Washington, D.C.: The Society, 1997: 42-47. ISBN: 1557524718 (Library of Congress).        2. Frans J. Van de Velde. Role of the scanning laser ophthalmoscope in photodynamic therapy of macular disease Publication: Proc. SPIE Vol. 3908, p. 190-201, Ophthalmic Technologies X; Pascal O. Rol, Karen M. Joos, Fabrice Maims; Eds. Publication date: June 2000.        3. Frans J. Van de Velde. Scanning laser ophthalmoscope optimized for retinal microphotocoagulation. Publication: Proc. SPIE Vol. 3564, p. 146-157, Medical Applications of Lasers in Dermatology, Cardiology, Ophthalmology, and Dentistry II; Gregory B. Altshuler, Stefan Andersson-Engels, Reginald Birngruber, Peter Bjerring, Adolf F. Fercher, Herbert J. Geschwind, Raimund Hibst, Herbert Hoenigsmann, Frederic Laffitte, Henricus J. Sterenborg; Eds. Publication date: February 1999.        4. Frans J. Van de Velde et Al. Scanning laser retinoscopy: a new technique for evaluating optical properties of the cornea after refractive surgery Publication: Proc. SPIE Vol. 3192, p. 187-194, Medical Applications of Lasers in Dermatology, Ophthalmology, Dentistry, and Endoscopy; Gregory B. Altshuler, Reginald Birngruber, Marco Dal Fante, Raimund Hibst, Herbert Hoenigsmann, Neville Krasner, Frederic Laffitte; Eds. Publication date: December 1997.        5. Frans J. Van de Velde. Scanning laser ophthalmoscopy: optimized testing strategies for psychophysics Publication: Proc. SPIE Vol. 2930, p. 79-90, Lasers in Ophthalmology IV; Reginald Birngruber, Adolf F. Fercher, Philippe Sourdille; Eds. Publication date: December 1996.        6. Volume 302 Proceedings of the Bull Soc Belge Ophtal, 2006, all papers.        7. Frans J. Van de Velde. Electronic Ophthalmoscopy: Functional 4-D imaging of the retina. Thesis Universiteit Antwerpen, 2009, ISBN 978-90-5728-224-9.        